642403 has 2 divisors, whose sum is σ = 642404. Its totient is φ = 642402.

The previous prime is 642373. The next prime is 642407. The reversal of 642403 is 304246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642403 - 2⁹ = 641891 is a prime.

It is a super-2 number, since 2×642403² = 825363228818, which contains 22 as substring.

It is the 802-nd Hogben number.

It is not a weakly prime, because it can be changed into another prime (642407) by changing a digit.

It is a nontrivial repunit in base 801.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321201 + 321202.

It is an arithmetic number, because the mean of its divisors is an integer number (321202).

2⁶⁴²⁴⁰³ is an apocalyptic number.

642403 is a deficient number, since it is larger than the sum of its proper divisors (1).

642403 is an equidigital number, since it uses as much as digits as its factorization.

642403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 642403 is about 801.5004678726. The cubic root of 642403 is about 86.2851092798.

Adding to 642403 its reverse (304246), we get a palindrome (946649).

The spelling of 642403 in words is "six hundred forty-two thousand, four hundred three".